NET INCOME (LOSS) PER COMMON SHARE - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator:
NET INCOME (LOSS)	$ (1,500)	$ 7,047	$ 22,251	$ (3,410)
Denominator [Abstract]
Weighted average common shares outstanding – Basic	46,947,621	46,542,556	46,889,913	46,241,578
Effect of dilutive shares:
Common stock equivalents arising from stock options and ESPP		90,398	5,948
Restricted stock awards and units and performance units		90,419	119,401
Weighted average common shares outstanding – Diluted	46,947,621	46,723,373	47,015,262	46,241,578
Basic (in dollars per share)	$ (0.03)	$ 0.15	$ 0.47	$ (0.07)
Diluted (in dollars per share)	$ (0.03)	$ 0.15	$ 0.47	$ (0.07)